[PATCH v3] git-p4: recover from inconsistent perforce history

[Andrew Oakley <andrew@adoakley.name>]

Perforce allows you commit files and directories with the same name, so
you could have files //depot/foo and //depot/foo/bar both checked in.  A
p4 sync of a repository in this state fails.  Deleting one of the files
recovers the repository.

When this happens we want git-p4 to recover in the same way as perforce.

Signed-off-by: Andrew Oakley <andrew@adoakley.name>
---
 git-p4.py                      | 43 ++++++++++++++++++++-
 t/t9834-git-p4-file-dir-bug.sh | 70 ++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+), 2 deletions(-)
 create mode 100755 t/t9834-git-p4-file-dir-bug.sh

diff --git a/git-p4.py b/git-p4.py
index b8b2a1679e..d551efb0dd 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -3214,6 +3214,42 @@ def hasBranchPrefix(self, path):
             print('Ignoring file outside of prefix: {0}'.format(path))
         return hasPrefix
 
+    def findShadowedFiles(self, files, change):
+        # Perforce allows you commit files and directories with the same name,
+        # so you could have files //depot/foo and //depot/foo/bar both checked
+        # in.  A p4 sync of a repository in this state fails.  Deleting one of
+        # the files recovers the repository.
+        #
+        # Git will not allow the broken state to exist and only the most recent
+        # of the conflicting names is left in the repository.  When one of the
+        # conflicting files is deleted we need to re-add the other one to make
+        # sure the git repository recovers in the same way as perforce.
+        deleted = [f for f in files if f['action'] in self.delete_actions]
+        to_check = set()
+        for f in deleted:
+            path = decode_path(f['path'])
+            to_check.add(path + '/...')
+            while True:
+                path = path.rsplit("/", 1)[0]
+                if path == "/" or path in to_check:
+                    break
+                to_check.add(path)
+        to_check = ['%s@%s' % (wildcard_encode(p), change) for p in to_check
+            if self.hasBranchPrefix(p)]
+        if to_check:
+            stat_result = p4CmdList(["-x", "-", "fstat", "-T",
+                "depotFile,headAction,headRev,headType"], stdin=to_check)
+            for record in stat_result:
+                if record['code'] != 'stat':
+                    continue
+                if record['headAction'] in self.delete_actions:
+                    continue
+                files.append({
+                    'action': 'add',
+                    'path': record['depotFile'],
+                    'rev': record['headRev'],
+                    'type': record['headType']})
+
     def commit(self, details, files, branch, parent = "", allow_empty=False):
         epoch = details["time"]
         author = details["user"]
@@ -3222,11 +3258,14 @@ def commit(self, details, files, branch, parent = "", allow_empty=False):
         if self.verbose:
             print('commit into {0}'.format(branch))
 
+        files = [f for f in files
+            if self.hasBranchPrefix(decode_path(f['path']))]
+        self.findShadowedFiles(files, details['change'])
+
         if self.clientSpecDirs:
             self.clientSpecDirs.update_client_spec_path_cache(files)
 
-        files = [f for (f, path) in ((f, decode_path(f['path'])) for f in files)
-            if self.inClientSpec(path) and self.hasBranchPrefix(path)]
+        files = [f for f in files if self.inClientSpec(decode_path(f['path']))]
 
         if gitConfigBool('git-p4.keepEmptyCommits'):
             allow_empty = True
diff --git a/t/t9834-git-p4-file-dir-bug.sh b/t/t9834-git-p4-file-dir-bug.sh
new file mode 100755
index 0000000000..031e1f8668
--- /dev/null
+++ b/t/t9834-git-p4-file-dir-bug.sh
@@ -0,0 +1,70 @@
+#!/bin/sh
+
+test_description='git p4 directory/file bug handling
+
+This test creates files and directories with the same name in perforce and
+checks that git-p4 recovers from the error at the same time as the perforce
+repository.'
+
+. ./lib-git-p4.sh
+
+test_expect_success 'start p4d' '
+	start_p4d &&
+	test_might_fail p4 configure set submit.collision.check=0
+'
+
+test_expect_success 'init depot' '
+	(
+		cd "$cli" &&
+
+		touch add_file_add_dir_del_file add_file_add_dir_del_dir &&
+		p4 add add_file_add_dir_del_file add_file_add_dir_del_dir &&
+		mkdir add_dir_add_file_del_file add_dir_add_file_del_dir &&
+		touch add_dir_add_file_del_file/file add_dir_add_file_del_dir/file &&
+		p4 add add_dir_add_file_del_file/file add_dir_add_file_del_dir/file &&
+		p4 submit -d "add initial" &&
+
+		rm -f add_file_add_dir_del_file add_file_add_dir_del_dir &&
+		mkdir add_file_add_dir_del_file add_file_add_dir_del_dir &&
+		touch add_file_add_dir_del_file/file add_file_add_dir_del_dir/file &&
+		p4 add add_file_add_dir_del_file/file add_file_add_dir_del_dir/file &&
+		rm -rf add_dir_add_file_del_file add_dir_add_file_del_dir &&
+		touch add_dir_add_file_del_file add_dir_add_file_del_dir &&
+		p4 add add_dir_add_file_del_file add_dir_add_file_del_dir &&
+		p4 submit -d "add conflicting" &&
+
+		p4 delete -k add_file_add_dir_del_file &&
+		p4 delete -k add_file_add_dir_del_dir/file &&
+		p4 delete -k add_dir_add_file_del_file &&
+		p4 delete -k add_dir_add_file_del_dir/file &&
+		p4 submit -d "delete conflicting" &&
+
+		p4 delete -k "add_file_add_dir_del_file/file" &&
+		p4 delete -k "add_file_add_dir_del_dir" &&
+		p4 delete -k "add_dir_add_file_del_file/file" &&
+		p4 delete -k "add_dir_add_file_del_dir" &&
+		p4 submit -d "delete remaining"
+	)
+'
+
+test_expect_success 'clone with git-p4' '
+	git p4 clone --dest="$git" //depot/@1,3
+'
+
+test_expect_success 'check contents' '
+	test_path_is_dir "$git/add_file_add_dir_del_file" &&
+	test_path_is_file "$git/add_file_add_dir_del_dir" &&
+	test_path_is_dir "$git/add_dir_add_file_del_file" &&
+	test_path_is_file "$git/add_dir_add_file_del_dir"
+'
+
+test_expect_success 'rebase and check empty' '
+	git -C "$git" p4 rebase &&
+
+	test_path_is_missing "$git/add_file_add_dir_del_file" &&
+	test_path_is_missing "$git/add_file_add_dir_del_dir" &&
+	test_path_is_missing "$git/add_dir_add_file_del_file" &&
+	test_path_is_missing "$git/add_dir_add_file_del_dir"
+'
+
+test_done
-- 
2.24.1